1. Field of the Invention
The present invention generally relates to the management of a system of stackable switches in a data communication network, and more particularly to Internet Protocol (IP) address resolution during fragmentation of a system of stackable switches.
2. Description of the Related Art
Network switch stacking technology allows the aggregation of several similar network switching devices for the purpose of creating a single larger (higher throughput) logical switch device called a stack. Once in a stack configuration, switch stack addressing logic typically is applied to determine which device will become the “master” of the stack with the other remaining devices becoming “members” of the switch stack. The system of stack switches is generally, for example, identified with one Internet Protocol (IP) address and one stack address. This makes the system of stackable switches appear as one logical unit, particularly, to external devices communicating with the system. By applying switch stack addressing logic, the switch members will “lose” their pre-assigned IP addresses and assume the IP address of the stack master.
The system of stackable switches is generally coupled in series and the topology of the system generally characterized by a closed loop called a ring or an open strand of switches referred to herein as a chain. Each of the stackable switches is adapted to perform switching between its own data ports as well as the data ports of other stackable switches by transmitting packets via the stack ports, that facilitate the efficient transmission and switching of these packets to the appropriate stack switch port.
In conventional network switch stacking systems, a problem arises whenever the switch stack becomes fragmented, e.g., as caused by a pulled connection cable, resulting in two or more fragmented stacks, where each of the two or more fragmented stacks will have the IP address of the original stack master. Such IP address duplication is prohibited and the conventional way to resolve such IP address duplication as a result of a fragmented stack is for a network or system administrator to manually reset the IP addresses.